EF core Migrations wrong latin SQL encoding

I have a ASP.NET Core 1.0 project with EF7. When I add a migration with SQL command and latin characters, I get them replaced by "?" when updating database.

Let's see an example:

public partial class TestEncodingMigration : Migration
{
    protected override void Up(MigrationBuilder migrationBuilder)
    {
        migrationBuilder.Sql(@"some text with latin chars : á é í ñ");
    }

    protected override void Down(MigrationBuilder migrationBuilder)
    {
    }
}

And this is the script I get from that migration:

PM> dnx ef migrations script <some prev migration> -c MyDbContext

some text with accent: ? ? ? ?
;

GO

INSERT INTO [__EFMigrationsHistory] ([MigrationId], [ProductVersion])
VALUES (N'20160216162901_TestEncodingMigration', N'7.0.0-rc1-16348');

As you can see, all latin characters have been replaced by "?"